[Safort]

pifon,
да вообще в лёгкую

<div class="block">
  <div class="in">in</div>
</div>
<div class="block">block</div>
<div class="block">block</div>
<div class="block">block</div>

<script>
  var blocks = document.querySelectorAll('.block');

  for (var i = 1; i < blocks.length; i++) {

    blocks[i].style.backgroundColor = 'red';

  }

</script>